Faulty relay?


#1

I have a 2003 Dodge Caravan. Recently I came home and parked the van, and I know for sure nothing was left on to drain the battery. When I went to start the van several hours later, it clicked a few times (sounding like a near dead battery) but eventually started up. But, as I drove off wondering what that was all about, I noticed the speedometer and tachometer were both pegged out all the way around on warp 10. Well, I promise I was not doing 210 MPH I swear! So, wondering what is going on I figured I would check into it the next morning. Lo and behold the next morning… the starter would click and click, but just didn’t have enough power to start up the van! Again, there was nothing left on to drain the battery. I’m wondering, before I take it to a local mechanic, am I having a problem with a faulty relay switch that is causing some sort of over-powering problem to my dash board. It’s only the speedometer and tach that were pegged out the previous night. The fuel gauge and temp gauge were both working fine.


#2

I would have the charging system checked out first. I sounds like you may need a new battery possibly and hopefully the alternator is ok. There may be some AC component coming from the alternator and the gauges are picking it up. You will need to replace the alternator in that case.


#3

It’s a simple matter to check for ac output from the alternator. With the engine running, set the multimeter on ac range, place the lead on the alternator output. Observe. The reading could be compared to the reading from another vehicle’s alternator.